The invention relates to improvements in methods of and in apparatus for manipulating receptacles which contain a particulate material, such as fragments of tobacco leaves, reconstituted tobacco and/or artificial tobacco. More particularly, the invention relates to improvements in methods of and in apparatus for transferring particulate material from a series of successive receptacles (e.g., cardboard boxes provided with covers or closures in the form of pivotable lids adapted to be moved between operative positions in which they overlie the open tops and inoperative positions in which they afford access to and permit evacuation of the contents of the respective receptacles) into a different receptacle or onto a takeoff or removing conveyor. The means for supplying at least partially filled receptacles to a transfer station can comprise a roller conveyor or another suitable transporting unit.
As a rule, the contents (such as tobacco particles in a cigarette making plant) of receptacles are evacuated by gravity flow. Thus, an oncoming receptacle is lifted off a transporting unit and is transferred to a position at a level above a stationary container, a container on a pallet or another suitable conveyance, or a removing conveyor prior to being turned upside down so that its contents can descend by gravity flow. This invariably entails a contamination of the surrounding atmosphere by minute particles of dust and/or by larger particles, as well as normally undesirable comminution (such as breaking) of shreds or analogous optimal configurations of the conveyed particulate material.